If tracing your Scottish roots, check out the French angle

[O'Callaghan]

I find it's usually best to start where you are most recently and then work backward through one's parents, grandparents, great grandparents, and so on wherever it may lead you. When people decide that they have an affinity for an ethnic group or place or period of history, and then try to shoe horn their research to fit into that direction, they often run into trouble, sometimes misleading not only themselves but other researchers who rely on their work.

I have all sorts of names in my family tree that can be either English or Scots. As I am actually from England myself, I feel it's safe to assume they are just English and not Scottish, lacking any evidence to the contrary. In fact, there is one name that can be Scottish, Dutch or Flemish, but we think it is more likely Flemish, because that branch came from a part of England where Flemish weavers are known to have settled in the 12th century - too long ago for it to be something we can ever hope to check out, but we have no reason to assume they came from Scotland.

OTOH, I would bet that many other people here in the US with similar family names would just go ahead and order a kilt in the tartan of the Scots' clan matching the name or a sept of it without doing any research. With a sept of a Scottish clan there are huge opportunities for mistakes, as a name can often be a sept of multiple clans, and there are almost always others of the same name that were not a sept of any of those clans, and in many cases never even had the slightest connection with Scotland.

I must admit that if I couldn't trace my roots back to the other side of the pond I would be tempted to do the same. Of course I can, because it was me who came over to the States and not some long lost ancestor, but I don't feel like being too hard on people in that position. It's a fair excuse to wear a kilt, if you need one. Fortunately, my Irish ancestry is pretty solid and has been traced back more than a century before they even went from Ireland to England.